Study: Quality of air warnings during wildfires did not have much impact
Posted October 21, 2026 10:47 am.
A new study by McGill University researchers has found air quality warnings during wildfires did not have significant impact on Montrealers movements.
According to the study when Environment and Climate Change Canada warnings urged Montrealers to limit outdoor activity during Canada’s worst wildfire smoke episodes, the city’s travel patterns shifted but not significantly.
Researchers examined how Montrealers were moving during 27 days, in 2022 through 2025, when smoke-related air quality advisories were in effect.
They found that, on those days, BIXI trips fell by 5.8 per cent, while bus ridership rose by 6.7 per and metro ridership rose by 4.7 per cent.
“While people moved from open-air travel into enclosed modes, which is what the bulletins ask for, the size of the change was small,” said study co-author Daniel Romm, a PhD candidate in the Department of Geography.
Recreational running – the activity that health bulletins caution against most directly – showed no statistically significant change at all, the researchers said. They measured this using data from the Strava running app, though they caution that limitations of the dataset may have affected the result.
“There are severe health risks from exposure to wildfire smoke, and, as wildfires increase their smoke is among the more costly and dangerous risks of the changing climate,” said Romm.
The researchers recommend pairing the advisories with incentives to encourage compliance.
“Advisories may need to be paired with practical measures that make compliance easier, such as temporarily reduced transit fares during smoke episodes, or employer support for remote work.”
